Could My Cat be Allergic to His Food??

Recently one of our clinic kitties, “O’Malley”, began vomiting and losing weight. In addition to blood work and fecal testing, we started a food trial on him. We initially saw improvement in both his weight and vomiting, but after 6 months, he began to show signs again which caused us to investigate his “compliance”. Below is a discussion of food trials, including reasons and pitfalls.

Cats can have reactions to food causing gastrointestinal signs (vomiting, diarrhea, decreased appetite, weight loss), sometimes skin signs (excessive licking or scratching, hair loss, skin irritations and lesions on the skin, lips, paw pads or ears), and even respiratory signs (coughing , wheezing, trouble breathing, asthma signs). Interestingly, allergies are not typically associated with sneezing or runny eyes in cats the way we think about it in people.

The reactions can be true allergies (involving an immunologic response) or non-immunologic (food poisoning, reactions to toxins or additives in the food).

Diet trails are recommended by your veterinarian to see if your cat’s clinical signs improve or resolve once the diet is changed. Trials can take anywhere from 2-12 weeks to see response. Blood testing for allergies measures levels of immunoglobulin E (Ig E) and is not accurate for food allergies or sensitivities because not all allergic reactions are mediated by IgE, nor or all food reactions mediated by the immune system.

The diets that are recommended may be single source protein and carbohydrate diets that your cat has never eaten or hydrolyzed protein diets (where the proteins are broken down so tiny as to not cause a reaction). A veterinary therapeutic diet is recommended because over the counter diets are often not pure and can still contain protein sources to which your cat has previously been exposed.

Pitfalls include supplementing your cat with treats or other food sources to which he is still sensitive or allergic to, feeding over the counter diets, cats not wanting the new food, or cross reaction between the protein in the recommended diet and a protein to which your cat is sensitive. Examples might be turkey cross-reacting with a chicken allergy.

You may need to keep your cat indoor to ensure he is not scavenging food at the neighbors’ and you may need to use dry kibble or baked canned of the prescription diet as treats so that visitors will not be tempted to feed your cat non-prescription treats. All medications should be checked to make sure they do not contain proteins in the liquid or capsule that could create reaction. This includes heartworm and flea medications.

In some cases you may chose to cook a homemade diet for your kitty. If so, it is recommended you consult with a board certified veterinary nutritionist to formulate your cat’s diet. Check the acvn.org website to find a nutritionist in your area.

So, what happened to O’Malley? Well, we ruled out clients and staff members as a source for “supplementation” of his diet and performed an abdominal ultrasound on him. The findings indicate some intestinal and liver disease that did not show up on blood work and is worsening despite the food trial. He is scheduled to have biopsies of his in the next week and we will keep you posted on his case!

Dr. McManis is an avid triathlete and is constantly training for races. She completed her first Iron Man in May of 2012. She is owned by 2 home kitties- Amante (“Monty”) and La Mariquita (“Mari”), and 2 hospital kitties- Momma Kitty and O’Malley.